Measurement of the Nucleon Strange-Antistrange Asymmetry at Next-to-Leading Order in QCD from NuTeV Dimuon Data

Abstract

We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the first to use a complete next to leading order QCD description of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma. We also report a new measurement of the charm mass.

Parton distributions for the LHC run II

“…In global fits, the strange PDF is mostly constrained by the neutrino-induced deep-inelastic scattering data, such as CHORUS, NuTeV and NO-MAD [36,37,169,170]. While also inclusive data is sensitive to strangeness, the strongest constraint come from the so-called dimuon process, charm production in charged-current DIS.…”

Measurement of the production of a W boson in association with a charm quark in pp collisions at $ \sqrt{s} $ = 7 TeV with the ATLAS detector

“…The s-quark PDF has been determined by neutrino-nucleon deep inelastic scattering (DIS) experiments [3,4] at momentum transfer squared Q 2 ∼ 10 GeV 2 and momentum fraction x ∼ 0.1. However, the interpretation of these data is sensitive to the modelling of c-quark fragmentation and nuclear corrections; some analyses [5][6][7] indicate that the squark sea is suppressed relative to the d-quark sea at all values of x while others [8] suggest that SU(3) symmetry is restored as x decreases.…”

“…The next-to-leading-order (NLO) QCD terms [2] are dominated by one-loop corrections to the subprocess gs → W c and the tree-level 2 → 3 processes gg → sW c and qs → qW c. Processes with charm quarks in the initial state are not considered for this analysis as explained in section 9.2. Since the gs → W c process and its higher-order corrections are dominant, the pp → W cX production is directly sensitive to the s-quark distribution function in the proton at momentum-transfer values on the order of the W -boson mass (m W ).The s-quark PDF has been determined by neutrino-nucleon deep inelastic scattering (DIS) experiments [3,4] at momentum transfer squared Q 2 ∼ 10 GeV 2 and momentum fraction x ∼ 0.1. However, the interpretation of these data is sensitive to the modelling of c-quark fragmentation and nuclear corrections; some analyses [5][6][7] indicate that the squark sea is suppressed relative to the d-quark sea at all values of x while others [8] suggest that SU(3) symmetry is restored as x decreases.…”

Higgs mass constraints on a fourth family: Upper and lower limits on CKM mixing

“…In the past, the EWWG has included the APV and NuTeV measurements but eventually omitted them from the fit because of concerns about systematics. Today, the original NuTeV result is no longer relevant because of a subsequent measurement by the NuTeV collaboration of an asymmetry in the nucleon " ss sea [33] as well as changes in several other related measurements. For the fits in [16], the NuTeV result was revised with four modifications of the original analysis; we prefer to omit the NuTeV measurement pending an authoritative analysis by the NuTeV collaboration itself.…”